Kidinnu (Greek Kidenas) has found an astrology (astronomy?) school in Sippar
c. 315 BC (see Schnabel 1923). He is credited (various sources) for having
calculated the length of the solar year (with an error of only 4 mn), of
being the inventor of the so-called "system B" (vernal point at 8 Aries), of
the relation 251 synodic months = 269 anomalistic months, & by Plinius of
knowing that Mercury is only 23 degrees far away of the Sun.